Cryostats integrating PTR cooling are usually designed such that no liquid cryogen is present in their operation—the absence of liquid cryogen represents their main advantage over the standard bath cryostats. Standard bath cryostats use one or more types of liquefied gases of various boiling temperatures in their operation. The subject invention combines all advantages of standard cryostats with the advantages of the PTR-based cryostats. The invention is intended for measurements in solid state physics, in particular of AC susceptibility.